Edge grinding machine



1970 i G. F. RITTER, JR, ET AL 3,525,182

EDGE GRINDING MACHINE Filed Feb. 29, 1968 3 Sheets-Sheet 1 INVENTORS -a/nd f/cd/nk Ca/awn ATTORNEYS 7 ET AL G. F. RITTER, JR.,

EDGE GRINDING MACHINE Aug. 25, 1970 Filed Feb. 29, 1968 3 Sheets-Sheet l5 INVENTORS 914x 6 1 Qua/6%. F C g nd C d 01072 9 Cewmwmm ATTORNEYS United States Patent 3,525,182 EDGE GRINDING MACHINE George F. Ritter, Jr., and Frank J. Carson, Toledo, Ohio,

assignors to Libbey-Owens-Ford Company, Toledo Ohio, a corporation of Ohio Filed Feb. 29, 1968, Ser. No. 709,434 Int. Cl. B24b 9/10 US. Cl. 51-101 2 Claims ABSTRACT OF THE DISCLOSURE A machine for grinding the edges of plates of glass or other materials having edge contours of varying radii and also of relatively small radius. A pair of grinding units, having grinding wheels rotatable about parallel vertical axes, are mounted in spaced side-by-side relation on a vertical support member which is pivoted in a supporting bracket to turn about a vertical axis, whereby the grinding wheels are caused to swing bodily about said axis as they traverse the curved edge of the glass plate, said vertical axis being located between the grinding units and forwardly of said support member such that the axes of rotation of the grinding wheels and the axis of bodily swinging movement of the grinding units define an obtuse angle. The grinding wheels are yieldably urged into engagement with the curved edge of the glass plate, with the bodily swinging movement thereof controlled by a template and template follower roll.

The present invention relates to improvements in edging machines and more particularly to machines for grinding the curved edges of plates of glass or other materials.

This invention contemplates an edging machine of the above character embodying two grinding units mounted side-by-side on a vertical support member which is pivotally mounted such as to permit the grinding units to swing horizontally as a unit about a common vertical axis during the grinding operation. The machine also includes a rotatable worktable for supporting the plate for grinding and a rotatable template of a contour conforming sub stantially to that of the plate being ground and template follower rolls carried by the support member and engaging said template for gauging the plate grinding action of the respective grinding wheel as the grinding wheels traverse the curved edges of the plates.

The primary object of the invention is the provision of means for mounting the grinding units in such a manner that the grinding wheels thereof can effectively and uniformly grind curved edges of varying radii to provide clean, smooth edges.

Another object of the invention is the provision of such a mounting means for the grinding units which will permit the grinding wheels to effectively grind edge contours of relatively small radius.

Still another object of the invention is to provide such a mounting means in which the axes of rotation of the grinding wheels are equally spaced forwardly and laterally with respect to the axis of bodily swinging movement of the grinding units.

A further object of the invention is to provide such a mounting means in which the spaced grinding units are mounted to swing as a unit about a common vertical axis which is located between the grinding units and defines with the axes of rotation of the grinding wheels an obtuse angle.

Other objects and advantages will become more readily apparent during the course of the following description when read in connection with the accompanying drawings.

3,525,182 Patented Aug. 25, 1970 'ice In the drawings wherein like numerals are employed to designate like parts throughout the same:

FIG. 1 is a side elevation of an edging machine constructed in accordance with the invention;

FIG. 2 is a top plan view thereof;

FIG. 3 is a side elevation of one of the grinding units and the mounting means therefor;

FIG. 4 is a front View of the grinding units;

FIG. 5 is a top plan view of the grinding units;

FIG. 6 is a rear view of the mounting means for the grinding units;

FIG. 7 is a vertical detail section taken along line 7-7 of FIG. 4;

FIG. 8 is a horizontal section taken along line 8-8 of FIG. 4;

FIG. 9 is a vertical transverse section taken along line 99 of FIG. 4; and

FIG. 10 is a diagrammatic view showing the relationship between the grinding units and the mounting means therefor.

Referring now to the drawings and particularly to FIGS. 1 and 2, the edging machine of this invention comprises an annular supporting base 10 provided with a centrally located worktable 11 mounted on the upper end of a vertically rotable spindle 12. Generally speaking, the worktable 11 carries a horizontal template 13 on its lower surface and also supports workpieces 14, such as plates of glass on its upper surface.

As viewed in FIG. 2, the outline of the template 13 is preferably formed to include at least two curved areas '15 which are shaped to the pattern of curvature to which the adjacent edges of the glass plates 14 are to be ground. The worktable 11 is thus provided with means for carrying at least two glass plates or workpieces '14 which are positioned in diametrically spaced relation on the worktable by clamping plates 16, each having a non-abrasive surface for engaging the respective workpiece.

The clamping plates :16 are mounted for vertical reciprocal movement by powered mechanisms such as air cylinders 17 carried by a vertically disposed wall 18 extending above the worktable; with the piston rods 19 of the air cylinders being attached to the upper surface of the clamping plates. As shown, two such clamping plates 16 and air cylinders 17 are provided for clamping each of the respective workpieces 14 against the upper surface of the worktable, with the workpieces positioned in such a manner that the edges to be ground extend beyond the edge of the worktable as shown in FIG. 1. With this arrangement, one workpiece to be ground may be secured to the worktable and subsequently removed at a point remote from the grinding mechanism, generally designated by the numeral 20, while the worktable is rotating and the grinding mechanism is finishing the edge of the diametrically located second workpiece clamped on the opposite side of the worktable.

The grinding mechanism 20 for edging the workpieces 14 comprises two grinding units A and B, each including a grinding wheel 22 which is adapted to be rotated about a vertical axis by means of an electric motor 23, with said grinding wheel being directly connected to a hub 24 on the output shaft of the motor. =Each grinding unit A and B is provided with a template follower roll 25 arranged in vertical axial alignment with the related grinding wheel 22. In this way, as the worktable is rotated, the grinding wheels of the grinding units A and B will operate in succession upon the curved edges of the glass plates, with their movements being controlled by the follower rolls 25 traversing the template areas '15.

The two grinding units A and B are mounted in spaced side-by-side parallel relation on a vertically disposed support member 27 that is adapted to pivot freely about one vertical axis while the grinding units A and B and the support member 27 can simultaneously pivot or swing bodily about a second vertical axis. As is believed apparent but which will hereinafter be more fully explained, the grinding mechanism is thus adapted to swing toward and away from the worktable 11 about the second vertical axis as the follower rolls traverse the outline edge of the template 13 and while the grinding units A and B and support member 27 are pivotally swung about the said first vertical axis as the rolls 25 follow the specifically curved areas of the template.

To this end, the vertical support member 27 for the grinding units A and B is generally supported for radial movement in a horizontal plane relative to the worktable 11 by a horizontal arm 28 that is equipped at one end with vertically aligned journaled bearings 29 for a pivot rod or axle 30. As shown in FIGS. 1 and 2, the pivot rod 30 is carried at its respective ends in brackets 31 secured to or integrally formed with one upright 32 of an inverted U- shaped frame 33 on the base 10 and which has a complementary upright 34 and a reinforcing cross-beam 35 therebetween. More particularly, the support member 27 is mounted for swinging or pivotal movement between the upper and lower ends of a C-shaped supporting bracket having a vertically disposed web 41 and forwardly di rected lower and upper arms 42 and 43 respectively; said web 41 and arms 42 and 43 being preferably channelshaped in cross section. In the area of the web 41, an en larged flange 44 is formed; said flange being secured by bolts 45 to the flanged end 46 of the arm 28. The lower and upper arms 42 and 43 constitute mounting means b (bottom) and t (top) for pivotal movement of the support member 27 about the said first vertical axis.

As viewed in FIG. 6, the support member 27 is substantially cruciform in outline, with a relatively wide body portion 49, a depending, relatively narrower leg portion 50 and an upwardly directed and relatively shorter narrow leg portion 51. At the extremity of each leg portion 50 and 51, an outwardly directed lug 52 and 53 respectively, is provided to contain bearing means by which the support member 27 will pivot or swing with reference to the O shaped supporting bracket 40. To reinforce the support member 27, a pair of vertically disposed ribs 54 are located on the back surface of the body portion in equally spaced relation from the vertical axis thereof.

The lugs 52-53 of support member 27 and the arms 42-43 ofthe supporting bracket 40 thus constitute the component parts of the pivotal mounting means b and t for supporting the support member 27 at the bottom and top of the supporting bracket 40. The bottom mounting means [1 is illustrated in FIG. 7, but it will be understood that the top mounting means t is structurally the same except that the parts thereof are inverted. Thus, there is fitted in the web '56 of the lower arm 42, a hub 57 having a bore 58 for receiving a pivot pin 59 having an enlarged head 60 abutting the adjacent end surface of the hub and an oppositely disposed threaded end 61. The lug 52 is pro- 'vided with an axially aligned bore 63 in which a bearing spacer 64 and a radial-thrust bearing means 65 are received on the pivot pin 59. The spacer 64 is supported on the top surface of the hub 57 and, in turn, supports the inner race 68 of the bearing means 65. A bearing locknut 69 on the threaded end 61 of the pivot pin 59 acts to urge a lock-washer 70 into engagement with the opposite surface of the inner bearing race 68. The lug 52 is retained in this bearing relation by the annular flange 71 of a closure cap 72; the flange 71 engaging the outer race 72 of the bearing means 65 and maintained thereagainst by bolts 73 passed through the cap 72 and threaded into tapped holes in the lug '52.

As earlier explained, the motors 23 of the grinding units A and B are mounted on the support member 27. More particularly, each motor is attached to a base plate that is adjustably carried by the body portion of support mem- 4 ber 27 to permit the related motor to be conveniently adjusted.

To this end, the casing 75 of motor 23 of grinding unit A is provided with a laterally directed mounting flange 76 by which the motor is bodily supported on a base plate 77. Similarly the flange 76 of the casing of motor 23 of the grinding unit B is supported on a base plate 78. As viewed in FIGS. 4 and 6, the base plates 77 and 78 are carried by the body portion 49 of the support member 27 and are adapted to be adjustably secured thereto. It wil be noted in FIG. 4 that the grinding unit B is indicated in phantom lines in order that the details of the related base plate 78 can be readily understood. The flange 76 of each motor casing is located on the respective base plate, said flange and base plate being formed with mating keyways 80 for receiving a bar-type key 81. The mounting flanges, in each instance, are secured in position by bolts 83 passing through said flanges and received in tapped holes 84 of the base plates.

The base plates are each mounted for vertical sliding movement relative to the support member 27 to facilitate vertical adjustment by providing bar-type keys 86 that are received in keyways 87 and 88, respectively, in the opposed surfaces of the base plates 77-78 and the body portion 49 of the support member. In any position to which the motors 23 are adjustably located on base plates 77 and 78, they are secured by bolt and nut fastenings 89 and 90; each bolt 89 passing through openings 91 in the outer marginal areas of the base plates and aligned slots 92 provided in the body portion 49 and receiving a nut 90 on the outer end thereof. The inner marginal area of each base plate is slidingly retained against the front surface of body portion 49 by means of T-shaped clamping blocks 93 attached to said body portion by bolts 94.

Means is herein provided for individually adjusting the position of each of the motors 23 upwardly or downwardly in relatively small increments by movement of their associated base plate 77-78. To this end, the base plate 77 is equipped, adjacent its upper outer corner, with an edge mounted L-shaped bracket 95 having a horizontally disposed leg 96 tapped to receive the threaded end 97 of a bolt 98; said bolt being supported in a plate 99 secured as by bolts 100 to the upper edge of the body portion of the support member 48. Beneath the plate 99, the shank of bolt 98 carries a pinned collar 101 whereby turning of the bolt head 102 acts to raise or lower the base plate 77 by the associated bracket 95 While being restrained from endwise movement relative to the plate 99. On its inner marginal area, the base plate 77 carries a so-called center adjusting bracket 105 having an arm 106 tapped to receive a bolt 107. As in the case of the bolt 98, the bolt 107 is carried by a support member 108, attached to the body portion 49 of support member 27 by bolts 109, and restrained from endwise movement by a fixed collar 110.

Thus, upon loosening of the nuts 83, the base plate 77 can be adjusted vertically as the bolt 98 is turned relative to the bracket 95 and the bolt 107 similarly turned relative to the bracket 10-8. The same is equally true with regard to the base plate 78 of the grinding unit B. In this instance, a bracket 112 on the upper corner of the base plate 78 receives an adjusting bolt 113 supported by plate 114 on the support member 27. The inner marginal area of this base platealso carries a bracket 115 which is tapped to receive bolt 116 that is supported by bracket member 117 secured to the base plate by bolts 118.

The support member 27 also carries the template follower roll 25 for each grinding unit which is spaced below and in axial alignment with the respective grinding wheel 22. Each of the template follower rolls 25 is in the form of an inverted cup having a frusto-conical periphery 120 and the roll is rotatably journaled in the lower horizontal portion .121 of a J-shaped arm 122 by suitable means (not shown). The upper end 123 of the vertical leg 124 of arm 122 is secured in a recessed groove 125 in the support member 27 by bolts 126 which pass through vertical slots 127 in the vertical leg 124 and are received in tapped openings in the support member. To effect vertical adjustment of the I-shaped arm 122 there is secured to the upper end of the support member 27 a horizontal plate 129 through which pass screws 130 received in tapped openings 131 in said arm. Thus, upon loosening of the securing bolts 126 and properly adjusting the screws 130, each arm and consequently the template follower roll 25 can be raised or lowered as desired with respect to the grinding wheel. As best seen in FIG. 8, the sides of the upper end 123 of the vertical leg 124 are engaged by guide bars 132 and 133 that are secured in the marginal areas of the grooves 125 by bolts 134.

The template follower rolls 25 are positioned to engage the rotating template 13 mounted below the worktable 11. Because of the conical shape of the periphery 120 of the roll, if the arm 122 is raised, the entire grinding unit associated therewith will be moved away from the edge of the workpiece 14 so that the finished size of the workpiece is larger. Conversely, in order to compensate for wear of the grinding wheel 22, the arm is moved downwardly to lower the roll 25, allowing the grinding unit to swing inwardly toward the workpiece. This either reduces the size of the finished workpiece or compensates for reduction in the working diameter of the grinding wheel.

In either event, these adjustments of one grinding unit will produce a pivotal swinging movement of the support member 27 about the axes of the vertically aligned pivot pins 59. Of course, if the same adjustment, i.e., upward or downward movement of the J-shaped arms 122, is made with regard to both grinding units A and B the resulting pivotal movement will be evidenced by rotation of the support member 27 and the arm 28 about the axis of the pivot rod 30.

Upon rotation of the worktable 11 in a clockwise direction, as viewed in FIG. 2, the grinding unit A will engage the workpiece first, followed by the grinding unit B. The grinding wheel 22 of unit A is therefore provided for rough grinding, while the grinding wheel of unit B preferably produces a finer or finishing grind. As the template 13 rotates, the template rolls 25 will move the grinding units bodily inwardly and outwardly according to the contour of the template, and simultaneously the support member 27 can swing about the pivot points b and t to permit the grinding wheels to traverse the edge of the workpiece 14.

The grinding units and mounting mechanism are mounted for swinging movement about the pivot rod 30 and are normally urged toward the worktable 11 through a suitable weight 135 carried at one end of a cable 136 which is trained about a pulley 137 supported by bracket 138, secured to the upright 32 of the frame 33 and a similar pulley 139; the opposite end of the cable being connected to the pivoted arm 28 by an eye-bolt .140 at a point spaced from the pivot rod 30.

In the operation of the machine, the weight 135 on the free end of the cable 136 will swing the grinding units A and B about the pivot shaft 30 to urge the template follower roll 25 into engagement with the template 13 carried by the worktable 11 which is supported and rotated by the rotating spindle 12. This will bring the grinding units into engagement with the edge of the workpiece to be ground, with the extent of grinding being determined by the location of the respective template rolls.

An important feature of this invention resides in the mounting of the grinding units with relation to the C- shaped supporting bracket 40 to enable the grinding wheels 22 to eifectively grind edge contours of varying radii and also of relatively small radius on the workpiece. Thus, as clearly shown in FIG. 5, the axis of rotation of the pivot pins 59 about which the support member 27 and the grinding units turn is located forwardly of the support member 27 and between the motors 23 of the grinding units. Otherwise stated, the axes of rotation of the grinding wheels are equally spaced forwardly and laterally from the axis of bodily swinging of the grinding units to define an obtuse angle, with the axis of bodily swinging movement of the grinding units being the point or apex of the angle.

With such an arrangement, and as shown diagrammatically in FIG. 10, a straight line C drawn through the axes of rotation of the grinding wheels d and e and second and third straight lines 1'' and g drawn between the axes of rotation of the grinding wheels and the axis h (defined by pivot pins 59) about which the support member 27 turns form an isosceles triangle, wherein the axis h constitutes the apex of the triangle and the two sides f and g form an obtuse angle as indicated at i. With this arrangement, the distance between the apex of the triangle and the base thereof is materially shortened along the line k, resulting in the distance between the two grinding wheels being increased. it has been found that this permits the grinding wheels to swing horizontally through an arc of smaller radius whereby the template rolls 25 can follow templates 13 having one or more areas of relatively small curvature. This also permits the use of smaller diameter grinding wheels, which results in an improved grinding action along curved edges of small or relatively sharp radius.

The term forwardly of the support member, means on that side of the support member facing the worktable.

A workpiece 14 is placed on the rotatable worktable and clamped thereto by applying air pressure to the cylinders 17 causing the plates 16 to clamp the workpiece on the top of the worktable. The workpiece is then carried by the rotating table past and in engagement with successive grinding units A and B to finish the edge of the workpiece according to the configuration dictated by the curved configuration of the template 113.

The grinding wheels are customarily supplied with a suitable coolant fluid to aid in the grinding operation. Such coolant may be fed to the grinding wheels in any suitable manner such as by means of nozzles 142 and 143 connected to feed pipes 144 and 145, respectively, leading from a common supply pipe 146. An annular shield 147 is preferably carried by the supporting base 10 to contain the coolant fluid.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred embodiment of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention.

We claim:

1. In an edge grinding machine having a base, a worktable for holding a flat workpiece with at least one edge thereof exposed, means for rotating said worktable about an axis normal to the plane of said workpiece, a support member, a pair of grinding units carried by said support member in spaced side-by-side relation, an edge grinding wheel carried by each grinding unit, means for driving said grinding wheels about axes parallel with the axis of rotation of the worktable, means acting on said support member to yieldably hold the grinding wheels in edge grinding engagement with the workpiece during rotation of the latter, a template also carried by said worktable and rotatable therewith, a template follower roll carried by each grinding unit and riding against the template to gauge the grinding action of the respective grinding wheel, and means for pivotably mounting said support member to swing about an axis parallel to the axes of rotation of the grinding wheels, said last-named axis being located between the said grinding units an equal distance from the axes thereof and within an area between but not including a line connecting said axes and a line parallel thereto and tangent to said grinding wheels on the side adjacent said support member.

2. An edge grinding machine as defined in claim 1, in which said means for pivotally mounting said support member comprises a supporting bracket having upper and lower horizontal arms, and aligned vertical pivot pins carried at the upper and lower ends of said support memher and journaled in the respective horizontal arms.

References Cited UNITED STATES PATENTS 2,597,180 5/1952 Reaser et a1. 5l101 OTHELL M. SIMPSON, Primary Examiner 

